> EA> If you would like to help to debug FreeCOM, I can > EA> forward you a longish list of comments / diffs. What > Do it. But I suggest, better to start from smaller/simpler things.
Well, by looking at the disassembly, I did find the problem which made FreeCOM try to access more or less random drives right after displaying the prompt and right before running a command (before calling muxae)... http://freedos.cvs.sourceforge.net/freedos/freecom/lib/cmdinput.c?revision=1.10&view=markup static void my_setcursortype( unsigned short state ) ... regs.r_ax = 0x0F00; intr( 0x21, ®s ); ... That was supposed to be an int 0x10, not an int 0x21. The current version of the code calls int 21.0f00 with more or less random values in all other registers. That function is "open file using fcb" and of course it is evil to call that with random arguments. Completely pointless for anybody but me, I have some more notes... The more ASM oriented among you should be able to verify that the first of the below functions is what the compiler makes out of my_setcursortype. No idea what the second one is, probably some "intdos" style wrapper function. The third looks like some LFN- support-conditional thing, somehow special-casing MKDIR. Maybe somebody who knows the sources well can point me to that place. The fourth part just contains notes about intr(). Enjoy ;-). Eric 8748: enter 0x14,0x0, push si, "ax"=0xf00, int 21.registers (at bp-0x14) si="ax" and 0xff, "ax"=0x100, ax=[bp+0x4] IF ax==0, [IF si==7, "cx"=0xb0c, go ELSE "cx"=0x607, go] ELSE IF ax!=1, go, ELSE IF si==7, "cx"=0x10c, go, ELSE "cx"=0x107, go go: int 10.registers (at bp-0x14), done 4C93: "ax"=[bp+0xc] "bx"=[bp+0x4] "cx"=[bp+0xa] "dx"=[bp+0x6] "di"=[bp+0x8] int 21.registers (at bp-0x14), if carry, return -1, else ax, done A9E1: "ax"=si=[bp+0x6] "dx"=[bp+0x4] "ds"=ds int 21.registers if (si==0x7139) && (("flags".carry!=0) || ("ax"==0x7100))) { "ax"=si shl 8, int 21.registers } ax = -("flags" and 1), return, done ...is that -1 if NC, 0 if CY...?? DC6D: Builds INT NN calling code on stack, 8b 6e de cd NN ca 02 00, or for int 25 / 26 different data structure: ax bx cx dx [tobepushed/bp] si di ds es flags callthat... copy back registers... push cs, call near iret... ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
